5.9 watts: The world’s most efficient high-end computer

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Dutch hardware hacker, Emile Nijssen (nickname Mux), claims he has built the world’s most efficient high-end desktop computer: An Intel Core i5-3570K with 16GB of RAM, 64GB SSD, and other assorted bits, that consumes just 5.9 watts when idling and 74.5 watts at full load. Your desktop PC, by comparison, draws around 30 watts while idle and 150 watts at full load (while playing Angry Birds, or surfing a Flash website).

Mux has a bit of a history when it comes to ultra-efficient computers: He built a 50-watt computer in 2008 (called Dennis), a 20-watt computer in 2010 (Dennis2), a 9.5-watt NAS last year (Floppy2), and now the 5.9-watt Fluffy2. Fluffy2 is currently just a headless motherboard, but it will eventually be built into an IPS LCD display to create a passively-cooled all-in-one PC that draws less than 20 watts — the most efficient high-end PC in the world. It’s worth noting that none of these figures include a discrete graphics card, but Mux points out that the i5-3570K finally has an integrated GPU (the Intel HD 4000) that can play most games — at a low resolution with no checkboxes enabled, of course.

How does one go about building a 5.9-watt computer? Well, fortunately Mux is one of those hardware hackers who takes lots of photos, produces his own illustrative diagrams and graphs, and records everything that he does in minute detail.

For a start, Fluffy2 is based on Intel’s DQ77KB mini-ITX motherboard and the Core i5-3570K CPU, which he then pairs with 2x8GB of of DDR3-1333 Crucial RAM, 64GB MyDigital SSD, Intel Ultimate-N WiFi card, and a Logitech wireless receiver. As-is, mostly thanks to Intel’s 22nm Ivy Bridge architecture, Mux says this is one of the most efficient PC setups possible, drawing just 11.6 watts when idle. To go from 11.6 to 5.9 watts — almost exactly half the power consumption — is rather impressive, though.

To do this, Mux does one thing that many of us have tried (undervolting) and one thing that you’ve probably never even considered: Modding the motherboard to be more efficient. Mux begins by analyzing the DQ77KB motherboard to discern the flow of power around the board, and the relationship between each of the components, yielding this diagram:

Then, using his well-equipped electronics lab, he works out how much power each component on the motherboard uses, including the all important conversion losses — the amount of electricity wasted as heat energy when power has to be stepped down from 12V to 5V, 3.3V, and around 1V for the CPU. He turns this data into a proportional diagram, and then a beautiful Sankey diagram:

With this data in hand, Mux went to work on the motherboard, adding a CPU voltmod other various voltmods — and then desoldering the PCIe slot, fan header, SATA ports, and an LED, to further reduce power consumption. The end result, if you look pretty closely, is pretty messy — including a few scorched components — but you can’t argue with a 50% reduction in power consumption. While the reduction in idle power consumption is the most important (most home/office PCs are idle 90%+ of the time), the 25% reduction in max load consumption (99.6W down to 74.5W) is also very significant.

It makes you wonder just how much power (and money) we could save if every computer was as efficient as Mux’s. It’s not like his modifications were particularly complex; Intel and other mobo makers could easily replicate Fluffy2 and bring such motherboards to the mass market. We are already seeing this at a data center level, with big web companies such as Google developing their own, highly-efficient hardware — and of course, when it comes to mobile PCs, reducing power consumption is one of the industry’s prime focuses.

In the future, Mux will post more details about Fluffy2, including detailed guides on how to perform the voltmods yourself, the home-brew UPS (built from a bunch of laptop batteries), and the case for the all-in-one computer (video below).

Did you turn something like speedstep off? If your CPU runs at full clock the whole time it’s gonna consume considerably much more power than it has to.
I run 2 watercooling circuits, 2x HD6970 with +50mhz core and +30mem, AMD 955@4.2GHZ, 2 samsung spinpoints and an OCZ vertex, (+some LEDs and fans and stuff) but I still idle around 50 watts, if I turn off those downclock features It’ll go up to 230 watts.

Yes, speedstep is enabled, but I know my setup is not power efficient (and it has been running 24/7 for about 5 years).
Well, that’s not an issue for me anyway…

James

Sorry, your answer is a fallacy. I have Athlon II x4 UNDERVOLTED which is draws significantly less than PII 955, one WD HDD and built-in 4200 IGP and idle is at 110W!
Scaling that, even if your HDDs are driven down, your usage will be as high as 150W due to CPU and two (again) idling video cards. At LEAST.

Most computers idle for something like 90% of their uptime, just FYI — not computers that are used for rendering or gaming, but normal office and home computers. 5.9 watts idle would be a HUGE power saving if it was replicated nationwide.

If you don’t set your machine to suspend when there is inactivity for a short period.. MY system hibernates after 5 minutes of inactivity, so that means .8 watts between power sessions… My high end power use is about the same, and I have made no mods.. (My video card isn’t quite as power hungry though)

I can play Skyrim if I want, about middle settings for everything, but then I never said I had a “High End” system…

Transcoding video is done in the GPU mostly, so my 2.8Ghz CPU barely has work to do…

Working for a television station, I do transcode a great deal of videos, I only require ~25-30 watts of power while I am working, and after 5 minutes of jobs finishing my PC switches to hibernation. (Wake up only takes a few seconds, so it’s no big deal… I won’t lose my job over the wasted 2-3 minutes a day waking it back up to continue)

I’ll take my sub-one-watt Hibernation over almost 6 watts of idle any day.

Seriously, Less than 7 seconds to resume is fine with me.

For a working machine you will not lose your job over an extra 6 seconds to get back to work…

For a kid wanting to resume WoW… well, that’s impatience… Let’s be real here, you’d have to live as an oxymoron to believe wake time isn’t worth cutting the idle wattage to 1/6 of the Modder’s specs. given the whole point of his mods is to save power…

Give it some thought….

For the record, my work rig is a laptop with a discreet GPU card…
When I play Skyrim ,or Angry Birds for that matter, I usually switch off the laptop panel and use a larger desktop monitor instead.

The real irony here is the “problem” is no one has tried to do this. They are afraid of the check list boogy man. What will I do if I can’t upgrade? My computer won’t be cool now because 2 years from now it will not upgrade to run product X. Of course, no one or almost no one actually does the upgrade, because in 2 years there is a better option that will upgrade to standard Y.

When Intel gets a fiberoptic thunderbolt to replace pci there would be no need for more than 3 or 4 connections to the motherboard. Usb 3.0, Thunderbolt by fiberoptic, power and ethernet would do it. The really cool idea would be to do build a pci over a fiberoptic thunderbolt connection to put a graphics card in it’s own box. A full size computer the size of a deck of cards with graphics card add on the same size. Cost would drop to about $50 each, and there in lies the rub. Until we got competition from ARM, Intel and Microsoft had no motivation to make this possible. They were strangling the baby before it could be born.

Maybe now that there is competition there will be innovation again. Here’s to hoping this happens. We could bring performance per watt back to it’s prior increasing rate if we killed all the unnecessary garbage on motherboards.

Hi, guys do not try to replicate this experiment. I have reeded on internet that Intel in the new BIOS has a excluded list of the CPUs. That list exclude the “K ” series CPUs. ” K series CPUs normally consume 77W power in stead of maximum 65W allowed by this board.If you by all the components may not work.

I think it is a little misleading to say he could do this while the world’s leading chip manufacturers could not. For one, chip manufacturers don’t have the luxury of knowing beforehand what their hardware configurations will be. Secondly, they certainly can remove I/O if their design spec requires it to be there. Good work, but still – it’s not as if these chip designers couldn’t accomplish this themselves.

Emile Nijssen

This is by far the best written article I’ve ever seen published about any of my projects. Love it! I usually don’t frequent this website but a friend of mine showed me this article. It’s very refreshing to see articles that don’t just copy part of my blog verbatim and slap random pictures in it.

I’d also like to respond to the questions in these comments. First of all, during any significant work Fluffy2 uses between 11 and 20W: whether it be watching HD youtube videos, playing Minecraft (yes… I confess), photoshopping, that kind of stuff. Basically, most tasks only use 1 core, the second core is loaded a bit and the rest of the cores are essentially off. Almost no GPU load. The 75W figure is extremely unlikely to ever happen in real use; it’s a figure I got with OCCT + Furmark. I never got a figure above ~50W in real use (even transcoding video).

Also, removing the SATA and PCIe ports didn’t do anything for power consumption per se, the main reason for doing that is simply because the motherboard is packed with stuff and I couldn’t get my soldering iron into the areas I needed to mod. I didn’t need them for my particular purpose so I just removed them. The board is actually still fully functional – I removed no functionality.

As for the sustainability of my mods: VRM and power supply efficiency will always be relevant. Whatever chips will be made in the future; they’re going to need VRMs to work and I’m here to optimize those. It’s the brunt of my mods.

And well, the graphics card. Yes, I am aware that HD 4000 isn’t high end, but to be fair it plays basically everything at ‘alright’ settings. You don’t even need to turn stuff to low – it’s a capable midrange-ish graphics solution. Currently, there is no real way to make discrete graphics cards sufficiently power efficient to have a place in these builds. Maybe next time. It’s my achilles heel. How cool would it be to have a sub-10W gaming rig with highend graphics?

Again thanks for this great article. I like to think I make polished and refined blog articles, but I recognize you, Sebastian, as an undeniably superior writer.

Hey! I love it when the creator/hacker/etc comes over here to comment :) Welcome!

Thanks for the kind words. I try my best! I was actually a bit cautious about writing it up, because you’re obviously not done yet — but I thought it was too cool not to cover… so… hopefully you’ll forgive me!

Thanks for the clarifications. Yes, I know removing the SATA port doesn’t cut down on power usage — but removing the LED does, right? :P

Is there really nothing you can do to reduce the power consumption of a discrete graphics card? Would certainly be pretty cool, if you could.

Emile Nijssen

I always try to visit the sites that feature me :) That’s what I do the blogs for, right?

Anyway, graphics cards are hard to mod for low power because they’re pretty closed platforms (Intel has awesome datasheets, nVidia and AMD don’t), they don’t follow any type of proper power management convention (like ACPI) and their power circuitry, especially on the high-end cards, is super exotic. I’ve seen Volterra hybrid MOSFET-magnetic-ICs on graphics cards a year before they lifted the NDA on that stuff for general electronics use. I get all excited at the thought of the power density of those converters… oh man.

But most importantly, only very recently have there been cards that can power gate those huge chips to reduce idle power consumption. If you bought any video card even as recently as 2011 you’d be guaranteed of 30 or 40W idle power use, just because the entire chip leaks current. That’s 8x my entire computer. That has no place in these extreme builds. You can’t combat chip leakage, undervolting only goes so far. 50% of a lot is still a lot.

Also, equally important, is the fact that GPUs by themselves have TDPs an order of magnitude higher than any other chip, including modern CPUs. Just the IA cores in my i5, the stuff that does useful calculations, uses 30W full load. A modern-day high-end GPU? 275W. It’s hard to optimize your power circuitry for those very low idle values if the max load is basically 2 orders of magnitude higher. There are ways – like using a separate switchable power supply for the GPU – but it’s not pretty. Even if I’ll be modding GPUs in the future, it will probably be something with a 100W TDP at maximum.

Consider the modern Kepler or GCN implementations of GPU’s in laptop chips. We’re talking 65w consumption for the 7970m when gaming at stock clocks. (even though the card is rated for 100w).
28nm has been a breakthrough of enormous proportions for performance / power rapports. These cards can idle at 15-16w without any serious mods. I know it’s probably not what you’re aiming for, but i don’t think the potential of a true high-end ultra-low-power PC is not achievable these days.

chuck

Hey Emile, how stable is it running at such low voltages? Do you get many appllication hangs/crashes?

I like projects like this. I have been building energy-effecient gaming PCs for years. It’s tricky, because you have to give up a wee bit of raw performance to drop the TDPs to reasonable levels. But it’s nice to have a gaming PC that doesn’t keep the AC running all day.

HampusGustafsson

Whats a “High end computer” in your eyes if a flash page or Angry Birds game puts your computer under full load?

I hope that this article is some kind of bad joke.

Its fairly missleading for people to read: “Compared to your high end pc” and then “50 watt…”

Mine is right now using around 100 watts. Its more like 300-400 watts when playing a game, and no, I am not talking about Angry Birds as a process-intensive game….

Mricehouse

The computer is an An Intel Core i5-3570K with 16GB of RAM, 64GB SSD, Not super high end but by far fast enough to run angry birds.

HampusGustafsson

“Full load” while playing Angry birds. I cant stop thinking about how bad that sounds.

Great to see attention being given to power usage. Of course, reducing the power used in a high-end machine, as opposed to using a low-end machine, which is what most users need anyway, will never give an earth-shattering reduction in total power consumption.

Taken that most active computer time is spent browsing the Internet, reading email, and watching video, a tiny computer like the $35 Raspberry Pi, which has a MAX power draw of 3.5 watts (700 mA at 5 V), or something like it, would do the trick.

An architecture that truly enables resources as they are needed, so it can scale from being an Internet browser to a high-end gaming machine, would be wonderful, but where is the incentive for the manufacturers? POWER sells, not lack of power CONSUMPTION.

Kudos to Emile for his efforts, though – great to see minds like that in action.

john

I am actually working on something similar, however I doubt that I would go into those hardcore undervolting and soldering simply because I’m horrible at it. i7-3632QM, mini-ITX motherboard, SSD, and so on. I’m also making the body out of the left over carbon fibre DIY

What a sad computer. At 74W you can power discrete GPU’s and undervolted pin-modded CPU’s with much, much higher performance.
Edit: Ah, I see that was during max-stress benchmarking situations. I apologize for the early remark.
@Emile: Due to the fact that you can’t claim a PC to be high-end without a proper graphics solution, have you considered using ULP-optimized components (such as laptop mobo’s, cpu’s and gpu’s) to get higher performance per watt?

saad

power can not be stepped down..It is the voltage and power is wasted in this process!

Emile Nijssen is so humble towards his creation, I find it inspiring! I’m so glad there are people out there who wouldn’t mind sharing such a ridiculously powerful creation without asking for any kind of compensation besides recognition! (: Thank you so much for this eye opening article!

john

If you were to add a discreet gpu to this device, what would it be? An MXM graphics with ridiculous PCIe adaptor? Cause at the moment desktop gpus have horrible idle draw and doesn’t do all that much more compared to the mobile ones

jim bob

Cool, I like the integrated 20w computer and monitor idea discussed in the video, great for mobile vehicle use like police, fire, rv’s, everywhere you need computing all the time at minimal power draw. Now lets see it run on 12v dc with minimal input/conversion losses and with wifi, bluetooth and rugged touch screen. I’ll beta test that in my RV since I need the computer up all the time, but live on batteries… Low power 20″ led monitors themselves use 20 watts minimum. This sounds like it could run most of the time at a lower power level than just an android stick and efficient led monitor.

Not bad. But you got to understand mobo manufacturers have to account for tens of thousands of configurations. So the wattage headroom must be quite high. He built a closed off system just for that specific processor specific amount of ram and everything. Still 75 watts on full load is amazing.

Ironbunny IonBunny

isn’t it because it’s custom made? If u want efficiency u have to sacrifice interchangeable parts. Ram has to be onboard. CPu onboard graphics onboard. Everything.

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